Brake



March 28, 1939. E LA BRiE A2,152,066

BRAKE Filed Sept. 9, 1935 .'5 Sheets-Sheet l AIl.:

INVEN TOR. 00am f. ae/

A TTORN E Y.

March 28, 1939. E. LA BRIE 2,152,066

BRAKE Filed Sept. 9, 1935 z sheets-sheet 2 INVENToR. unsere E. Mre/w A TTORNEYI March 28, 1939. L E. LA BRIE v 2,152,066

BRAKE Filed sept. 9, 1955 s sheets-sheet 3 270 A INVENTOR' .ll/06f@ f. nQ/Ef A TToRNEY,

Patented Mar. 28, 1939 v BRAKE Ludger E. LaBrie, South Bend, Ind., assignor to Bendix Products Corporation, South Bend, Ind., a corporation of Indiana Application September 4 Claims.

This invention relates to brakes and is illustrated by several embodiments of hydraulically .actuated internal expanding brakes of the duoservo type.

One of the objects of the invention is the provision of a hydraulically actuated brake suitable for trucks or other heavy duty automobiles.

A further object of the invention is the provision of means for cooling the hydraulic brake actuating cylinder while in use.

One feature of the invention is the provision of an offset portion formed in the backing plate though which air ows to cool the wheel cyln er.

Further features of the device disclosed, include the arrangement of the odset portion in such amanner'that it may serve as an anchor for the brake friction means, the provision of a scoop by which more eicient flow of air is obof connector for the shoes of the friction element,

and the arrangement of fixed and oating wheel cylinders within the recess formed by the offset portion in the backing plate.

Further objects and features of the invention will be apparent after a reading of the subjoined specification and claims and after a consideration of the accompanying drawings, 'in which:

Figure 1 is a View in section taken through a brake drum and disclosing one arrangement constructed according to my invention;

4 Figure 2 is a sectional view taken substantially on the line 2-2 of Figure 1;

Figure 3 is afragmentary sectional view taken -substantially on the line 3--3 of Figure 1;

Figure 4 is a view corresponding to Figure 1 showing a different form of brake constructed according to my invention;

Figure 5 is a, fragmentary view in section taken substantially along theline 5--5 of Figure 4;

.Figure 6 is a fragmentary sectional view taken substantially on the line 6-'6 `of Figure 4;

Figure 'l vis a View corresponding to Figures 1 and 4 and showing another brake constructed according to my invention;

Figure 8 is a fragmentary sectional view taken substantially along the line 88 of Figure 7; and

Figure 9 is a fragmentary sectional view taken substantially on the line 9-9 of Figure '7.

vseen that I have shown in Figures 1, 2 and 3 va brake comprising a backing plate I0, brake shoes I2 and I4, and a hydraulic actuating' cylinder tained, the pror/ision of a new. and improved type f Referring in detail to the drawings, it may be 9, 1935, Serial No. 39,736

(Cl. 18S-152) nut 22. 'I'he cylinder is formed with an inlet port 24 and with a bleed port 26, and is provided with pistons 28. The pistons 28 are arranged to actuate piston rods 30, which extend through openings in the portion I8 and contact with the ends of the shoes I2 and I4. Interposed between the opposite ends of the shoes is a novel type of adjustable connector or strut 32, which will be explained more in detail subsequently. Cooperating with the strut 32 is a spring 34 which urges the ends of the shoes toward each other and holds them in contact with the strut.` Adjacent the ends of the portions I8, the backing plate I0 is provided with anchors 36 and 38 which extend through pear-shaped openings 40 and 42 in the ends of the shoes I2 and I4 respectively. Adjacent to the openings 40 and 42vthe shoes are provided with relatively small openings 44 and 46, ,to which are connected the ends of a 'return spring 48. Secured to the backing plate I0 just beneath the portion I8 (see Figure 3) is a guide 50, which cooperates with the under side of the recess to position the spring 48.

In the operation of thi's form of my invention, fluid under pressure supplied through the opening 24 `causes a separation of the pistons 28 and through the piston rods 30 spreads the shoes I2 and I4 to contact with the rotating drum II. If the drum -is rotating in a counterclockwise direction, the shoe I4 becomes the primary shoe and through the strut-link 32 applies the shoe I2 to the drum and both shoes anchor through the shoe I2 to the anchor 36. Likewise, if the drum is rotating in a clockwise direction, both shoes anchor through the shoe I4 on the anchor 38. When the pressure in the fluid is relieved, the return spring 48 draws the shoes back into position shown. Wear of the shoes may be compensated by the strut 32. It is to be especially noted that the actuating cylinder I6 is separated from the drum and the shoes I2 and I4 by the backing plate IIJ and is thus insulated to a certain extent from the heat generated by the friction between the shoes and the drum. Thus the liquid in the actuating cylinder is protected to a large extent from the heat generated in braking. Moreovenpinasmuch as the recess Il!"l is exposedto the air through which the vehicle is traveling, the air current tends to keep the cylinder I6 and the liquid therein cooled to a normal temperature. l

In Figures 4, 5 and 6 there is shown a backing plate |I0, a drum III, shoes I I2 and I4, an actuating cylinder |I6, an adjusting strut |32, and return springs |34, |48, |49 and |49". The adjusting strut |32 is shown as a pair of threaded sleeves |328 and |32b with which there cooperates the screw |32o having right and left hand threads on opposite ends thereof respectivelyextending to'and cooperating with supplementary threads in the sleeves. IThe cylinder H6 is formed with one end closed, and the closed end has an extension it@ which is secured as at 162 to the adjacent end of the shoe H2. The cylinder is pro vided with a piston |28 and associated therewith is a piston rod 130 which extends through the end of the cylinder opposite to the extension it@ and thence into contact with the shoe lit.

The backing plate H0 is provided with an 0E- set member l i8 secured to said backing plate byr bolts and having a recess l i8a in which the cylinder M is positioned and the extension l5@ and the piston rod 130 extend through openings in the offset portion. The offset portion M8 is formed with a rounded surface at each end and the anchored ends of the shoes are arranged to cooperate with these rounded surfaces so that the onset portion of the backing plate forms the anchor for the shoes.

The operation of the brake shown. in Figures 4, 5 and 6 is substantially the same as that shown in Figures l, 2 and 3. However, in spreading the shoes the cylinder H5 is arranged to float and exerts a thrust on the shoe M2 through the extension i60. 'Ihe direction of rotation of the drum indicated by the arrow is the normal direction in forward movement of the vehicle, and by reason of the springs i159 and MSD, the shoe l ld moves rst into contact with the drum. The shoe i l2 in forward braking normally remains in contact with the offset portion and anchors thereon. In reverse braking, however, the shoe lid comes back to an anchoring position on the offset portion llt and then the cylinder il@ moves together with 'the extension 1GB and exerts brake applying force upon the shoe M2.

The arrangement shown in Figures 7, 8 and 9 Y is quite similar to that shown in Figures 1, 2 and 3.

However, instead of a standard backing plate a heavy casting 210 is secured as by bolts 252 to the axle 216i, and a light cover plate 216 is in turn secured to the casting 2li). The casting 210 is formed with an offset portion 218, which houses the cylinder 216. As shown clearly in Figure 8, this heavy casting also carries the anchors 236 and 238, and by means of the bolts of said anchors the cover plate 216 is secured to the casting.

A scoop 280 assures a suii'icient flow of air at all times to insure cooling of the cylinder ZIB. The shoes are arranged to be returned by return springs 23d and 235.

The construction of the strut 232, which corresponds exactly to strut 32 is shown most clearly in Figure '7.` Therein it may be seen that the strut member 282 contacting with the shoe 212 is formed with exterior threads and a sleeve member 28d is formed with interior threads'cooperating therewith. The sleeve 22M has one end 286 formed cylindrical to cooperate with the third element or member 288 of the strut which contacts with the shoe 2Id and which is formed with a bore 290. The members 232 and 288 are prevented from rotation by reason of the slot contacting the shoes 212 and 2id. Thus rotation of a wheel 292 secured to the sleeve 28B causes movement of the members 282 and 283 in opposite directions, thus spreading the shoes 2l2 and Elli. The spring 234 is arranged to hold the wheel 292 in any adjusted position. The operation of this form of device is exactly the same as that described above in connection with the forms shown in Figures 1, 2 and 3 and need not be repeated.

It may be thus seen that I have provided an efcient brake especially useful in connection 5 with heavy duty vehicles such as trucks. I have provided arrangements for maintaining the liquid of the wheel cylinders cooled in spite of the heat generated by the friction between the shoes and the drum. I have accomplished this by the use of an oset portion of the backing plate arranged with a recess outside of the backing plate in which the actuating cylinder for the brake is positioned. I have provided means for insuring a ow of cooling air through this recess to cool the cylinder 15 and have shown several embodiments, including a iixed cylinder and a iioating cylinder.

It is to be understood that the above described embodiments of my invention are for the purpose of illustration only and various changes may be 2@ made therein without departing from the spirit and scope of the invention. I claim:

1. In a brake, a rotating drum, a backing plate provided with an oiset portion having a recess 2 exterior of said backing plate from said drum, an actuating member including a cylinder positioned in said recess, shoes Within said drum adapted to be brought into contact therewith and arranged to anchor upon said offset portion, and 3( means extending through the walls of said offset portion andconnected with the actuating member for spreading said shoesvinto contact with said drum.

2. In a brake, a rotating drum, a backing plate 3,

provided with an oiset portion having rounded ends and having a recess exterior to said backing plate from said drum, an actuating member including a cylinder positioned in said recess, shoes within said drum adapted to be brought into con- 4,

tact therewith and arranged to anchor upon and be positioned by the rounded ends of said offset portion, and means extending through the walls of said oiset portion and connected with said actuating member-for spreading said shoes into 4 contact with said drum.

3. In a brake, a rotating drum, a backing plate provided with an offset portion having a recess exterior of said backing plate fromsaid drum, an actuating member including a cylinder positioned in said recess and unrestrained so that it is allowed to float within said recess, shoes within said drum adapted to be brought into contact therewith, and means extending through the walls of said oiset portion and connected with said actu- 5 ating member for spreading saidy shoes into contact with said drum.

' 4. In a brake, a rotating drum, a backing plate provided with an oset portion having a recess exterior of said backing plate from said drum, E

shoes within said drum adapted to be brought into contact therewith, an actuating member including an actuating cylinder secured to one of said shoes and a piston in said cylinder, a piston rod connected to said piston and to the other of said f shoes, and means extending through the walls of said offset portion and connected with said actuating member for spreading said shoes into contact with said drum.

LUDGER E. LA BRIE. 1 

